I. Field of the Invention
Increased amounts of insulation used in construction in recent years has caused problems relating to moisture control and inadvertent cold areas. These are new problems resulting from this additional use of insulation particularly in the rim joist area in modern standard construction techniques.
The rim joist boards extending around the periphery of a house were previously not insulated. The relatively large amount of heat loss through this vertical board was simply ignored. The present high cost of energy has resulted in using insulation, usually in the form of a fiberglas batt, fitted into the space between the floor joists on the sides where the rim joists are perpendicular to the floor joists, and attached along the rim joist on the sides where the rim joists are parallel to the floor joists. Using this approach it is essentially impossible to use a vapor barrier on the warm side of the insulation between the floor joists to keep moisture away from the rim joist because the insulation extends outward from the wall. The resulting moisture problem from this approach in homes only one or two years old has resulted in paint peeling from the outer surface of the exterior siding or the rim joists themselves rotting through. In some cases builders have attempted to cut and staple plastic sheeting over the insulation as a moisture barrier. Since the fiberglas insulation usually extends inward this is quite difficult. This approach is also very costly in the amount of labor required and unless a great deal of care is exercised in fitting the plastic sheating the vapor barrier is compromised with gaps and holes which leaves the problem unsolved.
Another problem related to the use of insulation occurs when the first floor of a dwelling is cantilevered outward as an extension from an exterior wall. This is a relatively inexpensive way of gaining additional space on the first and second floors, because the basement does not have to be increased in size to support this extension. The floor over this extension will become quite cold in the winter. This occurs because even if the extension is insulated under the floor, this merely slows the rate of heat flow which still results in a cold floor over the extension area.
II. Description of the Prior Art
A number of previous preformed members intended to be attached to building structures for various purposes have been patented. In Jonsson et al U.S. Pat. No. 4,446,661; Bentley U.S. Pat. No. 4,223,489; Kreimer U.S. Pat. No. 4,069,628; Reinke U.S. Pat. No. 1,924,515; Montgillion U.S. Pat. No. 498,563; O'Donnell U.S. Pat. No. 405,794; Clay U.S. Pat. No. 332,491; Samuelsson U.S. Pat. No. 4,679,370; and O'Brien U.S. Pat. No. 4,437,282, a variety of approaches in the use of preformed members adapted to control interior spaces and insulation, to provide moisture control and air gaps are disclosed. None of these inventions solve the specific problems addressed in the instant invention because these are new problems brought about by the new construction techniques discussed here.